Fabric puller mechanism for sewing machines



P 1937- G. SAUER El. AL

FABRIC FULLER MECHANISM FOR SEWING MACHINES 3 Sheets-Sheet 1 INVENTOR$=gafluuqr 1i; car Quasi,

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FABRIC FULLER MECHANISM FOR SEWING MACHINES Filed Dec. 17, 1955 aSheets-Sheet 2 7;? 1 9 55 5 5g 1 55 o a; I #7 1 -i v 75 1M l 7 75 J 55 o0 o l 5 /,I 5 9 59 6 5 I 52 J6 INVENTORS: Gem g5 Samar A.

By Oscar Quisf WORNEYS. g

P 7, 1937- G. SAUER ET AL FABRIC FULLER MECHANISM FOR SEWING MACHINESFiled Dec. 17,- 1935 s Sheets-Sheet s INVENTORSI Qeorga Saw 5.; Oscar47a;

Patented Sept. 7, 1937 PATENT OFFICE FABRIC FULLER MECHANISM FOR SEWINGMACHINES George Sauer, Berwyn, and Oscar Quist, Chicago,

Ill., assignors to Union Special Machine Company, Chicago, 111., acorporation of Illinois Application December 1'7, 1935, Serial No.54,806

12 Claims. (Cl. 112214) This invention relates to fabric puller meansadapted to function either alone or in an auxiliary capacity with theusual feed mechanisms of sewing machines in advancing the fabric inrespect to the needles.

Our invention is directed toward the provision of a mechanism which issimple in construction; which can be adjusted and relied upon tofunction in exact synchronism with the feed mechanism of a sewingmachine to advance the fabric without stretching or buckling it; andwhich moreover is smooth and balanced in its action so that the sewingmachine with which it is associated can be operated at high speeds witha minimum of noise and vibration.

The above indicated advantages we realize in practice, as hereinaftermore fully disclosed, in a puller mechanism wherein a pair of nip rollscooperate in drawing the fabric away from the seaming needle or needles,one of said rolls being positively driven intermittently throughactuating connections with a shaft from which the feed element of themachine derives its movements, in such manner that the feeding movementsof said roll are timed with the active'feeding movements of said feedelement.

Other objects and attendant advantages of this invention will appearfrom the detailed description'of the attached drawings, wherein Fig. Iis a view partly in side elevation and partly in longitudinal section,of a lock stitch sewing machine conveniently embodying our improvedpuller mechanism.

Fig. Il'nis an elevation of the front end of the machine with portionsbroken awayand others' sectioned for the better showing of importantstructural details. I

Fig. III is a bottom plan view of the machine; and 1 j m III. I j lThe'sewing machine herein illustrated is alock stitch machine of thetype featured in a co-pending applic'ationfserial No. 53,552 filed onDecember 9, 1935 in the names of Norman V.Christensen and Oscar Quist,having a vertically reciprocating needle bar l carrying two needles 2,

2a which cooperate with a pair of rotary hooks beneath the work support3 of the machine, one

of said hooks being shown at 4 in Fig. II. 'The a Fig. I V is astaggered transverse sectional" view taken as indicated bythe arrowsIV-'-,IY*in Fig.

port. By suitable means (not illustrated) within the head 5, up and downmovements are imparted to the needle bar I from a main shaft 8 whichextends longitudinally through the hollow of the arm 6 and is fitted atthe protruding right hand end with a combined hand and belt wheel 9 sothat the machine can be driven either manually or by power. 7 Extendinghorizontally beneath the work support 3 is a rotary shaft ill,

which, at an intermediate point, is journaled in a pendant bearing ll ofsaid work support 3. At the right hand end of the machine, the shaft Itextends through a bearing bushing l2 into a lubricant sump l3 locatedimmediately below and communicating with the hollow of the standard 1.Unison rotary motion is imparted to the shaft Ill "from the main shaft 8by a train of intermeshing gears l4, l5, and I6 within the standard 1and the lubricant sump I3. Connected to the forward end of the rotaryshaft In by a universal coupling comprehensively designated I1, is asupplementalextension Illa of said shaft,

' said extension passing through hollow journal members l8 and I9 todrive the rotary hooks 4 through suitable gear connections notillustrated. The journal members l8 and I9 are secured, to a pendantflange 20 of the work support by means of headed screws 2| and 22 withshanks extending through longitudinal slots 23, 24 in said flange sothat the rotary hooks can be accurately positioned independently forproper coaction with the respective needles '2 and 2a. Operating beneaththe work support 3 centrally between the journal'members l8 and I9 and'in line with the needles Z'and 2a is a feed'dog 25 which is secured,with capacity for vertical ad justment, to a feed bar 26 by means of aheaded has a portion 28 which extends forwardly above the supplementalshaft 10a, as well as a downwardly and forwardly curved portion 29 whichunder-reaches said shaft. At its end, the underreaching portion 29 ofthe feed bar 26 is pivotally connected to the suspension arm 30 of aneccentric strap 3| which embraces an eccen-' tric' 32 on thesupplemental'shaft Ilia whereby to said feed bar.

feed bar 26 extends tothe front of the machine forwardly of the needles2 and 2a, and is there pivotally connected at its endtoa bifurcatedrocker 33 on an oscillating shaft 34 journaled in spaced bearing lugs35, 36 and 31 depending from the work support 3. Secured to the shaft l0immescrew 21. As shown in Fig. II the feed bar 26 -therise and fallmovements are communicated From Fig. II it will be ob- .served that theover-reaching portion 28 of the diately to the right of the bearing IIis an eccentric 38 embraced by a strap 39. As shown in Fig. IV, anupward arm 48 of the eccentric strap 39 has a common pivotal connectionat 4| with the swinging end of a lazy bar 42 fulcrumed about one end ofa fixed stud 43 in a depending lug 45 of the work support 3, and withone end of a horizontal link 46. At its opposite end, the link 46 has apivotal connection at 41 with an actuating arm 48 on the oscillatingshaft 34. The pivotal connection 41 is adjustable along a curved slot'49 in the actuating arm 48, said slot having its center of curvaturesubstantially in the axis of the pivot connection 4| between the arm ofthe eccentric strap 39 and said link. By adjusting the pivotalconnection 41 along the slot 49 of the actuating arm 48 it is possibleto increase or decrease the oscillation of the shaft 34. The describedfeed mechanism, per se, constitutes the subject matter of anotherapplication, Serial No. 54,805 filed concurrently herewith in the nameof George Sauer.

The improved mechanism which we have devised for progressively drawingthe fabric away from the needles 2 and 2a. comprises a pair ofcooperating puller rolls 58 and 5| which are ar-,

ranged in superimposed relation, one above the work support 3 and theother below it, rearward of the presser foot 52 in respect to thedirection of fabric advance and comparatively close to the needle 2within the confines of said work support, such allocation of the rollsbeing possible due to the fact that the actuating elements for the feeddog are disposed at the front of the machine. The lower roll 58 issecured to a shaft 53 journaled at opposite ends in spaced pendantbearings 54 and 55 of the work support 3. As shown in Fig. II, the roll58 projects up through a clearance opening 55 in the work support 3 to alevel slightly above the top of said support 3. The roll 58 isintermittently rotated by a clutch device 56 which is preferably of thetype disclosed in U. S. Patent 1,692,130 granted to William B. Long etal. on November 20, 1928. The braking member 51 of the clutch device 56is secured to a lug 58 on the bearing 55 by screws 59, while the drivingmember 68 of said device has a slotted arm 6| which is coupled by meansof a horizontal link 62 with a pivot pin 63 at the swinging end of alazy bar 65 fulcrumed on the end of the fixed ,pin 43 hereinbeforereferred to opposite to that occupied by the lazy bar 42 of the feedmechanism. The driving member 68 of the clutch device 56 is actuated byan eccentric 66 on the shaft l8 at the left of the bearing through astrap 61 associated with said eccentric, said strap having an arm 68pivotally connected to the pin 63 of the lazy bar 65. The pivotalconnection 18 of the link 62 is adjustable along the. slot of the arm 6|of the clutch driving member 68 so that the circumferential shifts ofthe roll 58 can be made to oorrespond'exactly to the feed movements ofthe feed dog 25.

The idler roll 5| of the puller mechanism, re-

' volves freely about an axle 1| whereof the ends are secured by setscrews 12 in the extremities of a vertical carrier yoke 13, see Fig. II.As shown, the yoke 13 is in turn secured by set screws 15 to the lowerend of a presser bar I6 which is confined to axial movement invertically spaced guide lugs 11, I8 projecting laterally from the head 5of the arm 6. Rotation of the bar 16 is prevented through engagement ofa lateral projection I9 of a collar 88 thereon with a vertical guideslot 8| on the head 5. The idler roll 5| is yieldingly urged downward bya spring 82 which surrounds the presser bar 16 in the interval betweenthe top of the carrier yoke 13 and an abutment collar 83. As shown, thiscollar 83 has the form of a knurled finger nut and engages the threadeddownward extension 84 of a bushing 85 in the guide lug 18, which latteris split and pro-- vided with a clamp screw 86 whereby said bushing issecured. Obviously, by adjusting the finger nut 83, it is possible toregulate the force of the spring 82 and, in turn, the gripping pressureof the idler roll 5| upon the fabric which, during the operation of themachine, is passed between said idler roll and the driven roll 58. Inorder that the idler roll 5| may be lifted clear of the fabric andlocked in raised position when desired or required, there is provided afinger lever 81 which is fulcrumed about a screw stud 88 on the guidelug 18, and which is formed with a shouldered cam portion 89 forcooperation with a projection 98 of the collar 88 on the presser bar 16.

During operation of the machine, the feed dog 25, by coaction with thepresser foot 52, progressively advances the fabric in respect to theneedles 2 and 20. in the direction indicated by the arrow in Fig. II. Atthe same time, the cooperating rolls 58 and 5| assist in the feeding byprogressively drawing the fabric away from the needles 2 and 2a. As theshaft l8 rotates, the eccentric 66 moves the eccentric strap 61 (Fig.IV) back and forth, the pivotal connection 63 being confined by the lazybar 65 to swing in an are having its center in the axis of the fulcrumpin 43. Accordingly, the movement of the eccentric 66 is communicatedsubstantially direct to the link 62 with impartation, in turn, of afixed oscillatory swing to the driving arm 6| of the clutch device 56,and a corresponding rotary shaft to the roll 58. By adjusting thepivotal connection 18 of the link 62 up or down along the slotted arm 6|of the clutch driving member 68, the feeding movements of the roll 58can be increased or decreased to correspond exactly to the feedingmovements of the feed dog 25 so that the fabric is advanced withoutattendant stretching or buckling. The eccentrics 38 and 66 are of courseaccurately set on the shaft initially to predetermine synchronousoperation of the feed dog 25 and the puller roll 58. The idler rollmaintains the fabric in gripping pressure contact with the surface ofthe driven roll 58, and can yield upwardly against the pressure of thespring 82 to facilitate passage beneath it of fabrics of differentthicknesses. Due to the suspension of the pivotal connection 63, joiningthe eccentric strap 61 and the link 62 by the lazy bar 65, thefunctioning of the puller mechanism is rendered easy and smooth, and byvirtue of like functioning of the feed mechanism, the'combined action ofthese mechanisms is balanced to a degree which favors high speedoperation of the sewing machine with absence of excessive noise andvibration.

By suitable modifications within the scope of the appended claims, ourimproved puller mechanism is adaptable to sewing machines having feedmechanisms other than of the type herein shown and described forconvenience of exemplification, without sacrifice of any of the advan-'tages which have been pointed out.

Having thus described our invention, we claim: 1. Fabric pullermechanism for sewing machines comprising a fabric-engaging roll, adevice for intermittently rotating the roll, a shaft, an eccentric onsaid shaft, a strap embracing the eccentric, a link connected at one endwith a driving member for the device aforesaid, and havingits other endpivoted to an arm on the eccenstrap, and a lazy bar fulcrumed to swingabout a fixed center and supporting the pivotal connection between thelink and the eccentric strap'arm in suspension.

3. Fabric puller mechanism for sewing machines comprising a fabricengaging roll, a device for intermittently rotating the roll, a shaft,an eccentric on said shaft, a strap embracing the eccentric, a link witha pivotal connection at one end adjustable along a driving arm for thedevice aforesaid, and with its other end pivoted to an arm on theeccentric strap, and a lazy bar fulcrumed on a fixed center and havingits swinging end connected at the pivot between the link and theeccentric strap arm.

4. Fabric puller mechanism for sewing machines comprising afabric-engaging roll, a device for intermittently rotating the roll, ashaft, an eccentric on said shaft, a strap embracing the eccentric, alink with a pivotal connection at one end adjustable along a driving armfor the device aforesaid and with its other end pivoted to an arm on theeccentric strap, and a lazybar fulcrumed to swing about a fixed centerand supporting the pivot between the linkand the eccentric strap arm insuspension.

5. Fabric puller mechanism for sewing machines comprising' a pair ofcooperative nip rolls to engage the fabric between them, means foryieldingly urging the rolls toward, each other, a device forintermittently rotating one of said rolls, a shaft, an'eccentric on saidshaft, a strap embracing said eccentric, a link connected at one endwith a driving member for the device aforesaid and having its other endpivoted to an arm on the eccentric strap, and a lazy bar fulcrumed on afixed center and having its swinging end connected at the pivot betweenthe link and the eccentric strap arm.

6. Fabric puller mechanism for sewing machines comprising a drivenroller and a cooperat ive idler roller between which the fabric ispassed, a presser bar with a yoke bearing in which the idler roller isjournaled, an adjustable spring influential upon the bar to yieldinglyurge the idler roll toward the driven roll, a device for intermittentlyrotating the driven roll, a shaft, an eccentric 'on said shaft, a strapembracing the eccentric, a' link connected at one end with a drivingmember for the device aforesaid and having its other end pivoted to anarm on the eccentric strap, and a lazy bar fulcrumed on a fixed centerand having its swinging end connected at the pivot between the link andthe eccentric strap arm.

,7. In a sewing machine having a feed element;

' fabric puller mechanism operative in synchronism with the feed elementand comprising a fabric- 'engaging roll, a device for intermittentlyrotating the roll, a shaft, an eccentric on. said shaft, a

strap embracing the eccentric, a'link connected at one end with adriving member, for the device aforesaid and having its other endpivoted to -an arm on the eccentric strap, a lazy bar fulcrumed on afixed center and having its swinging end connected at the pivot betweenthe link and the eccentric strap arm, and means whereby the feedingmovements of the fabric engaging rolls aforesaid can be adjusted tocorrespond exactly with the feed movements of the feed element of themachine.

8. In a sewing machine having a feed element; fabric puller mechanismoperative in synchronism with the feed element and comprising afabricengaging roll, a device for intermittently rotating the roll, ashaft, an eccentric on said shaft, 1

a strap embracing. the eccentric, a link with a pivotal connection atone end adjustable along a driving arm for the device aforesaid so thatthe feeding movements of the fabric engaging roll can be regulated tocorrespond exactly to the feeding movements of the feed element, saidlink having its other end pivoted to an arm on the eccentric strap, anda lazy bar fulcrumed on a fixed center and having its swinging endconnected at the pivot between the link and the eccentric strap arm.

9. In a sewing machine having a feed dog receiving its feed movementsthrough oscillation of a shaft with an arm thereon connectedby a link tothe strap arm of an eccentric on a rotary shaft, and said eccentricstrap arm pivotally connected to a lazy bar swingable about a fixedcenter; fabric puller mechanism. adapted to operate in synchronism withthe feed bar and. comprising a fabric-engaging roll, a device forintermittently rotating the roll, another eccentric on the rotary shaftaforesaid, a strap embracing the last mentioned eccentric, a linkconnected at one end with a driving member for the device aforesaid andhaving its other end pivoted to an arm on the last mentioned eccentricstrap, and a lazy bar fulcrumed on the fixed center aforesaid and havingits swinging end connected at the pivot between said last mentioned linkand said last mentioned eccentric strap arm.

10. In a sewing machine having a feed dog receiving its feed movementsthrough oscillation in synchronism with the feed bar and comprising afabric engaging roll, a device for intermittently rotating the roll,another eccentric on the rotary shaft aforesaid, a strap embracing thelast mentioned eccentric, a link connected at one end with a drivingmember for the device aforesaid.

and having its other end pivoted to an arm on the last mentionedeccentric strap, a lazy bar fulcrumed on the fixed center aforesaid andhaving its swinging end connected at the pivot between said lastmentionedlink and said last mentioned eccentric strap arm, and meanswhereby the feeding movements of the fabric engaging roll can beadjusted to correspond exactly with the feed movements of the feed dog.

11. In a sewing machine having a feed dog receiving its feed movementsthrough oscillation of a shaft with an arm thereon connected by a linkto the strap arm of an eccentric on a rotary shaft, and said eccentricstrap arm pivotally connected to a lazy bar swingable about a fixedcenter; fabric puller mechanism adapted to operate' in synchronism withthe feed bar and comprising a fabric engaging roll, a device forintermittently rotating the roll, another eccentric on the rotary shaftaforesaid, a strap embracing the last mentioned eccentric, a linkconnected at one end with capacity for adjustment along a driving armfor the device aforesaid so that the feeding movements of said roll canbe made to correspond exactly with the feed movement of the feed dog,said last mentioned link having its other end pivoted to an arm on saidlast mentioned. eccentric strap,.and a lazy bar fulcrumed on the fixedcenter aforesaid and having its swinging end connected at a pivotbetween said last mentioned link and said last mentioned eccentric straparm.

12. In a sewing machine comprising a Work support, a needle operatingabove said work support, a feed dog and a rotary shaft beneath saidsupport, a feed dog carrier, means for imparting horizontal or feedmovements to the feed dog carrier disposed forward of the needleincluding an arm overreaching said shaft, an eccentric on the said shaftfor imparting lift movements to the feed dog carrier, a strap engagingthe eccentric and having a suspension arm pivotally connected to an armon the feed dog carrier underreaching said shaft; the combination offabric puller mechanism operated in synchronism with the feed dog, saidpuller mechanism comprising a pair of superposed fabric-engaging rollsrespectively above and below the work support and immediately rearwardof the needle in the direction of feeding.

GEORGE SAUER.

OSCAR QUIST.

